1999 Firebird with M90 conversion

[VF1Skullangel]

Re: 1999 Firebird with M90 conversion

I don't think Gm would have considered it. Think about it why would you invest in a V6 that can be capable to keep up with an Ls1 then your buyers would opt for the more fuel efficient V6 Supercharged than buy a V8.

That and it would have been stepping on LT1 Toes. :D Not only better fuel mileage but probably better performance. Just look at what the L67 did for the GTP imagine that in a Camaro/Firebird from the factory? I wouldn't even consider a V8 unless it was a C5. :)

[Sailor77]

Re: 1999 Firebird with M90 conversion

There is a lot of detail here, impressive work!

[Oldsaddict]

Re: 1999 Firebird with M90 conversion

Hey guys, sorry for not being on much for any updates on this build. I had the car a few days early this summer for some maintenance work and to investigate a plug wire related misfire, but otherwise is still running well and he had a ram air WS6 hood put on the car from another car at our shop and sets it off nice! Track season is about over and Im not sure it will have a chance to get there this year but would be nice to see how it runs. I will post up if the car makes it to the track.

[r_simmonds]

Re: 1999 Firebird with M90 conversion

I'm not sure why they didn't go ahead and build the supercharged versions of the 4th gens. I know they built 2 for testing. One was an L67 with the Holden blower, the other was a 4.3 but I don't remember what type of blower was on it. I know they seriously considered it for a while, but the project was cancelled.

[FirebirdGT]

Re: 1999 Firebird with M90 conversion

I'm not sure why they didn't go ahead and build the supercharged versions of the 4th gens. I know they built 2 for testing. One was an L67 with the Holden blower, the other was a 4.3 but I don't remember what type of blower was on it. I know they seriously considered it for a while, but the project was cancelled.

http://www.firebirdgt.com/SC%20Firebirds.htm
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[WarShrike]

Re: 1999 Firebird with M90 conversion

It IS unfortunate. They probably would have had to either Beef up the T5 or mount the T56 to it. But the close output numbers between the LS1 and the L67 in an F-body would have made for too much competition.

Maybe if they'd done a Firebird GTP/GXP in limited production, that would have been pretty nifty.

[Hose-B]

Re: 1999 Firebird with M90 conversion

It is the stock pcm but reprogrammed. This is the 4th rwd boosted setup I have done with a F-body pcm and they work fine just take a bit of time to tune and I have a baseline to start with since I have done similar before. Idealy it would be nice to use a fwd pcm from an L67 car but several problems arise, at least with an auto trans. The 99+ cars make it worse since they are drive by wire.

So reading up on this I was just wondering, if you use a L67 pcm for the swap and are going over to a t-5 . Would it be simpler that way, cuz I imagine some programming being done because the pcm will be looking an auto trans.

[mjshealy]

Re: 1999 Firebird with M90 conversion

I know this thread is a couple months old, but there really isn't any info about L67 top swaps.
IMO, it would be easier to use an L36 pcm. Either way youre going to have to tune. I will be performing this same top swap in April, have the parts and majority of accessories.

There literally is NO info on these top swaps, if the OP is around I have lots of questions.
Mainly about rear supercharger clearance. I'd like to know if I can use supercharger without modifying the housing, mount a 3/16" steel plate to the SC where the throttle body goes and have an immediate U-bend cut close to relocate the throttle body.

[FirebirdGT]

Re: 1999 Firebird with M90 conversion

I'd like to know if I can use supercharger without modifying the housing, mount a 3/16" steel plate to the SC where the throttle body goes and have an immediate U-bend cut close to relocate the throttle body.

No - must be modified. Look in "Stickies" for more project examples.
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[mjshealy]

Re: 1999 Firebird with M90 conversion

Where did you cut the housing for the intake, and how did you plug the coolant passages? Did you cut the housing all the way down, or leave the bottom intact?

[mjshealy]

Re: 1999 Firebird with M90 conversion

And also, I see in your pics where you cut the housing for the supercharger, and then covered it and coated it with something to seal it... What did you coat it with?
I just cut my housing today, and I'm trying to figure out the best way to make the connection... I don't really think j.b. weld will work here lol